1. Field of the Invention
The present invention relates to an improvement in a saddle type vehicle provided with a secondary air supply system.
2. Description of Background Art
A saddle type vehicle is known that is provided with a secondary air supply system for clarifying an exhaust gas by combustion of unburned components present in the exhaust gas. See, for example, Japanese Patent No. 4704127, FIG. 2.
As shown in FIG. 2 of Japanese Patent No. 4704127, an air cleaner (17) (parenthesized reference symbols appearing herein are the reference symbols used in Japanese Patent No. 4704127) is disposed on an upper side of an engine (E) mounted on the saddle type vehicle, and a secondary air supply system is disposed between the air cleaner (17) and an exhaust passage (35) extending from the engine (E). The secondary air supply system includes a secondary air inlet passage (36) through which cleaned air is supplied into the exhaust passage (35).
The engine (E) mounted on the saddle type vehicle in Japanese Patent No. 4704127 is a two-cylinder engine in which the two cylinders are arranged in a row along the transverse direction of the vehicle. In a V-type engine in which a plurality of cylinders are arranged in a V-shaped configuration with a crankshaft at the vertex of the V shape, a preferable layout for the secondary air supply system may be different from that in the above-mentioned type.
It is desired to develop a technology that enables an efficient and compact layout of a secondary air supply system in a so-called V-type engine which includes a front-side cylinder or cylinders and a rear-side cylinder or cylinders.